"The introduction of Steam to Ubuntu demonstrates growing demand for open systems from gamers and game developers," David Pitkin, director of consumer applications at Ubuntu maker Canonical, said in a statement. "We expect a growing number of game developers to include Ubuntu among their target platforms."

Valve is celebrating the launch with a week-long sale: through 13:00 EST (18:00 GMT) on 21 February, more than 50 Linux titles are available for 50 to 75 per cent off their original prices. Additionally, the free-to-play game Team Fortress 2 is offering a limited-time exclusive in-game freebie: Tux, the Linux mascot, can be carried by any of the game's classes and traded between players.

Valve confirmed in July that it was building a version of Steam for Linux to run on Ubuntu 12.04. The move was sparked in part due to company head Gabe Newell's concern that Windows 8 would turn out to be "a catastrophe for everyone in the PC space."

A closed Steam for Linux beta launched in early November, touting the free-to-play Team Fortress 2 game, another 24 Steam titles available on Ubuntu, and Valve's Big Picture mode. This latest release also works with Steam's Big Picture mode, which emerged from beta in December. It lets users ditch the keyboard and mouse, and kick back on the couch with a traditional video game controller.

"With Steam for Linux and Big Picture mode, Valve anticipates a growing number of gamers will use Steam in the living room," the company said.

"We're huge fans of Linux. It's like the indie OS-a perfect home for our indie game," Alen Ladavac, CTO of Croteam and creator of the Serious Sam franchise of games, said in a statement. "And who better to lead the charge into Linux gaming than Valve? With Steam distribution on Windows, Mac OS, and now Linux, plus the buy-once, play-anywhere promise of Steam Play, our games are available to everyone, regardless what type of computer they're running. That's huge."